Elasticity of cross-linked semiflexible biopolymers under tension
Abstract
Aiming at the mechanical properties of cross-linked biopolymers, we set up and analyze a model of two weakly bending wormlike chains subjected to a tensile force, with regularly spaced inter-chain bonds (cross-links) represented by harmonic springs. Within this model, we compute the force-extension curve and the differential stiffness exactly and discuss several limiting cases. Cross-links effectively stiffen the chain pair by reducing thermal fluctuations transverse to the force and alignment direction. The extra alignment due to cross-links increases both with growing number and with growing strength of the cross-links, and is most prominent for small force f. For large f, the additional, cross-link-induced extension is subdominant except for the case of linking the chains rigidly and continuously along their contour. In this combined limit, we recover asymptotically the elasticity of a weakly bending wormlike chain without constraints, stiffened by a factor four. The increase in differential stiffness can be as large as 100% for small f or large numbers of cross-links.
Keywords
Cite
@article{arxiv.1305.1049,
title = {Elasticity of cross-linked semiflexible biopolymers under tension},
author = {Alice von der Heydt and Daniel Wilkin and Panayotis Benetatos and Annette Zippelius},
journal= {arXiv preprint arXiv:1305.1049},
year = {2014}
}
Comments
11 pages, 6 figures, submitted to PRE